<template>
  <div class="todo-footer">
    <label>
      <!-- 思路:v-model直接绑定给我们设置的计算属性(计算属性可读可写) -->
      <input type="checkbox" v-model="allIsChecked" />全选
    </label>
    <span> <span>已完成0</span> / 全部3 </span>
    <button class="btn btn-danger">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "Footer",
  props:['todoList','checkAllhandle'],
  computed:{
    allIsChecked:{
      set(value){
        //还是调用app传来的修改所有done的方法
        this.checkAllhandle(value)
      },
       get() {
        /* 
        every:返回布尔值，遍历数组,如果每次回调函数都返回true,则every返回true,只要有一个回调返回false,则停止遍历,every返回false
      */
        return (
          this.todoList.every((item) => item.done) && this.todoList.length !== 0
        );
      },
    }
  }
};
</script>

<style scoped>
/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}
</style>